In the native distribution area it grows from 0-1800 m, from sand to silt soils, and in locations where there is some available water in the soil.

Even though it’s legally considered as being an invasive in Portugal, its distribution is still limited in our country.

Impacts on ecossystems

It can potentially form dense thickets, inhibiting the development of native vegetation.

It produces a lot of nitrogen-rich litter, which promotes soil change.

Economic impacts

It has potential expensive control measures.

Other impacts

The robust thorny stipules cause injuries, inhibit the presence of animals and hamper control operations.

Controlling an invasive species demands a well-planned management, which includes the determination of the invaded area, identifying the causes of invasion, assessing the impacts, defining the intervention priorities, selecting the adequate control methodologies and their application. Afterwards it is fundamental to monitor the efficiency of the methodologies and recuperation of the intervened area as to perform, whenever necessary, the follow-up control.

The control methodologies used for Acacia karroo include:

Physical control

Hand pulling: preferential methodology for seedlings and small plants. When in more compacted substrates, pulling must be made during the rainy season as to facilitate the removal of the root system.

Cutting: preferential methodology for adult plants. Cut the trunk as close to the ground as possible by using manual and/or mechanical equipment. It should be done before seed maturation.

Prescribed fire

It may be strategically used to favour germination of the seed bank, e.g., after the control of adult individuals (with the adequate management of the resulting biomass) and the subsequent elimination of seedlings. This method provides an advantageous reduction of the seed bank, both by destroying part of the seeds or by stimulating the germination of the remainders.

Visit the webpage How to Control for additional and more detailed information about the correct application of these methodologies.

Invasive Plants

Many ecosystems in Portugal are deeply affected by invasive species, either animal or plants. This means considerable economical losses, huge impacts on biodiversity, changes in the ecosystems services and even public health issues.

Our goal is to explain this problem, educating not only the common citizen but also specialized technicians to recognize and control invasive species.